Current Issue : October - December Volume : 2015 Issue Number : 4 Articles : 7 Articles
This paper presents the numerical density derivative approach (another phase of numerical well testing) in which each fluid�s\ndensities around the wellbore are measured and used to generate pressure equivalent for each phase using simplified pressure density\ncorrelation, as well as new statistical derivative methods to determine each fluid phase�s permeabilities, and the average\neffective permeability for the system with a new empirical model. Also density related radial flow equations for each fluid phase\nare derived and semilog specialised plot of density versus Horner time is used to estimate k relative to each phase. Results from 2\nexamples of oil and gas condensate reservoirs show that the derivatives of the fluid phase pressure-densities equivalent display the\nsame wellbore and reservoir fingerprint as the conventional bottom-hole pressure BPR method. It also indicates that the average\neffective ????ave ranges between 43 and 57mD for scenarios (a) to (d) in Example 1.0 and 404mD for scenarios (a) to (b) in Example 2.0\nusing the new fluid phase empirical model for????estimation. This is within the ???? value used in the simulation model and likewise that\nestimated from the conventional BPR method. Results also discovered that in all six scenarios investigated, the heavier fluid such as\nwater and the weighted average pressure-density equivalent of all fluid gives exact effective k as the conventional BPR method.This\napproach provides an estimate of the possible fluid phase permeabilities and the % of each phase contribution to flow at a given\npoint. Hence, at several dp???? stabilisation points, the relative ???? can be generated...
Infrastructures are considered as important facilities required for every country and society to be able to work properly. Aging\nand deterioration of such structures during their lifetime are a major concern both for maintenance researchers in the academic\nworld and for the practitioners. This concern is mainly because the deterioration increases the maintenance costs dramatically\nand lowers the reliability, availability, and safety of the structural system. Preventive maintenance and inspection activities are the\nmost usual means for keeping the structure in a good condition. This paper utilizes the concept of delay-time for developing the\noptimal inspection policy for deteriorating structures. In the proposed stochastic model, discrete times of inspection activities are\ntaken as the decision variables of an optimization problem, in a way that the obtained aperiodic (non uniform) inspection schedule\nminimizes the total downtime ratio of the structure. To illustrate the model capabilities, various numerical examples are solved and\nresults are compared with the traditional periodic (uniform) inspection policies. The results indicate the substantial reduction in\nsystem downtime due to the wisely planned inspection schedule and the appropriate utilization of delay-time concept, which is\nindeed a powerful framework for inspection optimization problems....
Heat transfer characteristics of fuel assemblies for a high flux research reactor with a neutron trap are numerically investigated in\nthis study. Single-phase turbulence flow is calculated by a commercial code, FLUENT, where the computational objective covers\nstandard and control fuel assemblies. The simulation is carried out with an inlet coolant velocity varying from 4.5 m/s to 7.5 m/s in\nhot assemblies. The results indicate that the cladding temperature is always lower than the saturation temperature in the calculated\nranges.The temperature rise in the control fuel assembly is smaller than that of the standard fuel assembly.Additionally, the assembly\nwith a hot spot is specially studied, and the safety of the research reactor is also approved....
India takes privilege of being an important place in mica industry of the world. The three important mica producing belts namely the Bihar Mica Belt, the Nellore Mica Belt and the Rajasthan Mica Belt are chief producers of mica of very good quality. Due to few problems, there is gradual decline in the production of mica from these three belts and on accounts of this many exponents have started believing that the mica industry may extinct. Further in recent past, many efforts have been made by developed countries to find substitute of mica for the purposes of replacing mica and its products but those substitutes are not perfect substitute of mica and are not very much cost effective. In recent times, there is cumulative effort on the part of several agencies to develop more scientific and technical norms for the prospecting of mica and in the last few years, the combined activities of geological, geophysical, remote sensing and geochemical methods have helped a lot in this direction. However it is doubted whether these concerted efforts will be fruitful or not on account of uncertain future and poor economic health of mica mines. The central agencies such as Geological Survey of India, the Mineral Exploration Corporation, the Indian Bureau of Mines and the Mine and Mineral Trades Corporation should take up some pilot areas and undertake exhaustive prospecting and exploration of mica. This paper will highlight problems prevailing in mica mining in India and its remedial measures for sustainable mica mining. In fact there are bright prospects for this industry even today. Only a realistic, proper and dynamic policy is required for this....
Breakthrough curves for citric acid adsorption from aqueous solution onto ion-exchange resin at 20, 35, and 55?C have been\ninvestigated. To predict breakthrough curves, threemathematical models have been analyzed based on the values of the least square\nmethod parameters, Durbin-Watson test, and mean relative percent error and, finally, appropriate models have been achieved.\nModels are in good agreement with experimental data based on the results. To examine models reliabilities and accuracy, models\nhave been compared by various breakthrough curve data obtained by other investigators.The results show appropriate agreement\nand in some cases regression errors have been reduced to less than 1.0 percent...
Based on the requirements for remote handling maintenance (RHM) of China Spallation Neutron Source (CSNS) multilayered\npipes, pipes cutting tests were performed under remote handling maintenance conditions. In this study, the results were obtained\nfrom different cutting directions and supporting intensities of pipe baseplates comparisons: When enough power was provided\nand the blade gripper did not slip, the cutting direction had little impact on the cutting capacity but more on the fault surface; the\nclearance between the blades caused the rotating torque; for remote handling maintenance, good horizontal support of the long handled\nlever of the hydraulic cutter was required. Significant conclusions were made for multilayered pipe cutting that are crucial\nfor auxiliary tools development for remote handling maintenance...
Investigation of the properties of neutron noise induced by localized perturbations in a sodium-cooled fast reactor has been\nperformed using amultigroup neutron noise simulator. Three representations of the noise source associated with the perturbations\nof absorption, fission, and scattering cross sections, respectively, were assumed to be located at the first fuel ring around the central\nassembly.The energy- and space-dependent noise, that is, the amplitude and the phase, was calculated in a wide range of frequencies,\nfor example, 0.1ââ?¬â??100Hz. The results show that in the important energy range (>1.0 keV) where the noise amplitude is significant the\nphase is almost constant with energy at the calculated frequencies despite the source types. At low frequencies, the variation of the\nphase is negligibly small at a large distance from the source. The perturbation in several fast groups has a significant contribution\nand dominates the amplitude and the phase of the induced noise....
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